Questions tagged [solid-state-chemistry]

Study of chemical species that are in solid phase, either in cases of their properties, or about ways of synthesizing them.

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27
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2answers
2k views

What makes Gorilla Glass more durable with each generation?

Gorilla Glass (GG) is one of the most recognizable brands of toughened glasses today, thanks to their marketing and widespread usage in various gadgets and automobile industry. According to Wikipedia,...
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0answers
26 views

How do hard drives store information using magnetic layering? (Antiferromagnetic/ferromagnetic films)

I am doing some work with solid state materials in some chemistry courses and I've been doing some research into exactly how a hard drive stores information as 1's and 0's. It seems like a bunch of ...
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2answers
278 views

Calculating the strength of an ionic bond that contains poly-atomic ions

So the bond association enthalpy for ionic compounds like $\ce{NaCl}$ and $\ce{NaBr}$ can be easily calculated from a Born-Haber cycle. But the way a Born-Haber cycle is constructed it uses info that ...
3
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1answer
934 views

Calculating the ionic polarizability from the Clausius-Mossoti relation

The concentration of atoms in a crystal is $N_d = \pu{2.24e28 m-3}$, and the relative dielectric constant is $\varepsilon_{r} = 5.62$. The crystal has a refractive index of $n = 1.5$. Using the ...
-1
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1answer
39 views

Concentration of electrons in silicon sample with a phosphorus dopant

I'm studying electrical and computer engineering and all I remember from chemistry is from high school. We have a $\ce{Si}$ sample and we want to replace one in every million atoms with a phosphorus ...
3
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0answers
1k views

Comparison between Boron Nitride and Graphite: Interlayer distance

Boron-nitrogen chemistry has attracted significant attention, partly because a B–N unit is isoelectronic with C–C. Furthermore, the radius of carbon and its electronegativity are roughly the average ...
6
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0answers
1k views

Can a solid be both crystalline and amorphous? [closed]

The first line in the Wikipedia article for "Glass" reads: Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage in, ...
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1answer
5k views

Contribution of Tetrahedral and Octahedral voids in HCP

I cannot find anywhere what the contribution of atoms situated at octahedral or tetrahedral voids in a HCP unit cell would be. I need to know this to be able to calculate the formula of a compound ...
7
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1answer
904 views

How to predict the 31P NMR spectra?

What can I predict about the $\ce{^{31}P}$ spectra of $\ce{TiP2O7}$? To get the required information about the crystal structure of the compound Here is a screenshot from the ICSD ...
0
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0answers
33 views

Oxidation states of Cu in YBa2Cu3O6 based on crystal structure [duplicate]

How does on go about this? I understand There is a +5 charge distributed on 3 copper ions. So either we have 2+, 2+ and 1+ or 3+, 1+, and 1+. Judging from the structure there are to unequivalent types ...
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0answers
332 views

Conversion of graphite into diamond [duplicate]

The standard state Gibbs free energies of formation of C(graphite) and C(diamond) at $T = \pu{298 K}$ are $\pu{0 kJ mol-1}$ and $\pu{2.9 kJ mol-1}$, respectively. The conversion of graphite [C(...
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2answers
9k views

What are some materials that expand a lot proportionally to heat?

There's never any source on the internet that can simply give me a list of materials that have the kinds of properties I'm looking for. I'm wondering what materials, like for a solid block of ...
1
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1answer
33 views

Is there any book or text where ionic radius of elements are given?

So my research has me looking for ionic radius characterization. If anyone could post any link or give the name of any book where ionic radius of all elements are given that would be really great?
7
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1answer
128 views

Why do we need to add hydrogen to amorphous silicon?

I was recently studying about Staebler-Wronski effect observed in amorphous silicon (a-Si). I realised it was due to imperfections in the lattice structure and breaking of Si-Si bond to Si-H bonds. ...
0
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0answers
428 views

Packing fractions of HCP and FCC

The packing fractions of hexagonal close packed unit cell and face centred cubic unit cell come out to be same when calculated geometrically. Is it just a coincidence? Differently put, could it be ...
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0answers
16 views

charge transfer between layers of graphite with stacking fault

As a general rule, we only expect two parts of a system to have the exact same amount of charge if they are symmetry-related to each other. How much charge transfer would occur in graphite with a ...
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2answers
6k views

Cubic lattice: How corner atom of a cube is shared by 8 atoms? [closed]

Each atom is at the corner of a cube and 8 cubes meet at each corner. Therefore each atom is shared by 8 cubes. But I can't imagine it in space, so please tell how I visualize it.
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2answers
309 views

Chemical formula of fluoroapatite

My textbook says the formula for fluoroapatite is $\ce{CaF2 * 3Ca3(PO4)2}$, whereas according to Wikipedia it's $\ce{Ca5(PO4)3F}$. What is the correct chemical formula of fluoroapatite and why there ...
3
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1answer
259 views

What does x mean in (1-x)A – xB composite materials, molar ratio, weight ratio or volume fraction?

I've been collecting data about ceramic materials and often I get to see composite materials are described as $(1-x)\ce{A} - x\ce{B}$. I am confused what this $x$ means. And I haven't seen any of the ...
6
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2answers
548 views

What is the structure of N₅P₃?

What is the structure of the molecule $\ce{N5P3}$? $\ce{N5P3}$ is not documented online, so could anyone please comment on the structure of the molecule: How many ligands does each phosphorous atom ...
-2
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1answer
300 views

Is there an element with no liquid state? [closed]

I know this question might be dumb but, is there an element that will go directly from solid to gas, with almost no visible or no liquid state? Just a random curious question.
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1answer
252 views

How does lime prevent soda lime glass from dissolving in water?

How does lime addition as an ingredient prevent soda lime glass from dissolving in water? Does it form calcium silicate in the process of melting?
3
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1answer
180 views

Influence of the neighbouring molecules in a crystal at the example of XeF4

For reasons of symmetry I (without deeper chemical knowledge) supposed, that $\ce{XeF4}$ has a shape like $\ce{CH4}$. But according to Wikipedia its crystalline structure was determined by both NMR ...
1
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1answer
31 views

Silver in defect chemistry

When talking about conductivity in combination with lattice defects you can often see that AgX is taken as an example for a Frenkel defect where the $\ce{Ag^+}$ moves to intersticial voids. I remember ...
3
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3answers
291 views

How do I know crystal structures from formula?

Give an explanation why $\ce{MgF2}$ and $\ce{CaF2}$ adopt different structure types. For example, the structure of calcium fluoride is 'fluorite' and the structure of magnesium fluoride is 'rutile'. ...
2
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1answer
52 views

vapor pressure of one part of binary compound

Let's say we have a binary compound AB in an enclosed container, and let's say there's a tendency to form B-vacancies so that B atoms/molecules escape and form a vapor. Let's assume there's enough of ...
2
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0answers
257 views

Putting high symmetry points labels to a band structure plot

So far I've got this plot using Quantum Espresso. I want to put gamma, X, L, etc labels to the k-path. Quantum Espresso's ouput states the following: ...
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1answer
804 views

Comparing the Lattice energy of different compounds

I am confused about some concepts related to Lattice energy. First of all,how to compare lattice energy between $2$ compounds belonging to different groups and periods? 1.Between $\ce{AlF3}$ and $\...
1
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1answer
294 views

Why can't two Silicon tetraoxide tetrahedrons share an edge or a face?

Our teacher told us about structural types of silicate minerals (neosilicate, sorosilicate, cyclosilicates ...) saying that those tetrahedrons can only share one corner (oxygen), but he didn't give us ...
1
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1answer
36 views

Effective diffusion coefficient of a species in a heterogeneous mixture

I want to calculate the effective diffusion coefficient of hydrogen radical in a mixed-phase consisting of metal oxide, metal hydride and metal. I consider the interfaces to be diffuse. How can I ...
3
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1answer
165 views

Why does the barium ion in barium titanate move in its tetragonal crystal structure?

Barium titanate is known in the materials science world to be a great dielectric. This is known to be because the $\ce{Ba^2+}$ ion sits off center in the middle of the tetragonal crystal structure. ...
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0answers
29 views

Diffusion equation I can't seem to find anywhere

So I was looking through some old lecture notes from a few years back when I stumbled upon a useful and simple equation that should, according to my former professor describe the diffusion in solid ...
0
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1answer
78 views

How does a molecule find the lowest energy state? [closed]

I understand that in a crystal lattice the molecule will tend towards the structure that is the lowest in energy (fcc, hcp, ccp, etc.). How does the molecule find these lowest energy states? Is it ...
3
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1answer
76 views

Does a molecule need to be placed symmetrically in the unit cell?

I was watching an OCW by MIT (3.091X) on solid state. My previous notion of lattice point and unit cell got shattered after this example. Where are the unit cell and lattice points in this picture? ...
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1answer
74 views

Solid structures related question [closed]

In which of the following compounds are all tetrahedral voids vacant? $\ce{NaCl(s)}$ $\ce{CaF2(s)}$ $\ce{ZnS(s)}$ $\ce{Na2O(s)}$ Kindly explain what this question asks from me and provide a ...
22
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4answers
4k views

How does NaCl maintain its crystalline structure?

My understanding is that $\mathrm{NaCl}$ is an ionic compound, in which $\mathrm{Cl}$ becomes (effectively) $\mathrm{Cl^-}$ and $\mathrm{Na}$ becomes $\mathrm{Na^+}$. So I understand why I would get a ...
6
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2answers
4k views

Yellow color of NaCl

My book says: $\ce{NaCl}$ shows metal excess defect, which results into the formation of an F-center in the crystal. This F-center is responsible for the yellow color of $\ce{NaCl}$. How does an F-...
2
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2answers
3k views

Understanding Equivalent Wyckoff positions

I'm somewhat confused by the concept of Wyckoff positions in crystal structures. From Quantum Chemistry of Solids by Robert Evarestov, the definition of a Wyckoff position is "all the crystallographic ...
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1answer
794 views

Coordination number of spheres (all identical) in hexagonal close packing (HCP)

I was revising solid state chapter when I came across this question What is the maximum coordination number of an atom in a hcp crystal structure of an element? The word 'maximum' drew my ...
7
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2answers
12k views

What is the reason for isotropy in amorphous solids?

In my book, it's been mentioned that crystalline solids are anisotropic whereas amorphous solids are isotropic in nature. The reason for these has been explained (with a diagram) as: Crystalline ...
3
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2answers
493 views

In a copper wire, how many electrons does each atom give away?

As an ion, copper can give off 1, 2, 3 or 4 electrons. But it has 1 s electron in the last shell and 10 d electrons. So as a metal, how many of those are delocalised and free to move around, and how ...
3
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1answer
2k views

ABC arrangement of FCC/CCP

I know that FCC shows ABC type but I am confused about it. For simple cubic and body centered, it is pretty easy to work out the packing arrangement but FCC is giving me a headache. What is this ...
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0answers
114 views

NiO and ZnO electrical conductivity with oxygen pressure

NiO is a Mott-Hubbard insulator and increasing oxygen concentration leads to anion excess and oxidation of Nickel so electron hopping is more favourable so electron repulsion is reduced and it becomes ...
2
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0answers
51 views

Band alignment of heterojunctions

I have seen several band bending diagrams in journals and the web. However, I am not sure as to how they align them. Some diagram appear to align the vacuum level and some align them by Fermi Level. I ...
0
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1answer
944 views

Zinc oxide reduction in ethanol

I'm trying to prepare a ZnO thin film deposited on a glass substrate. The precursor solution prepared by sol gel process through dissolving 1 M zinc acetate dihydrate $\ce{Zn(CH_3COO)_2.2H_2O}$ in ...
0
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1answer
768 views

How can a vacancy defect be a stoichiometry defect?

NCERT (India) explain stoichiometric defects as those defects which do not disturb the stoichiometry of the solid. Vacancy defects are stated to be under the category of stoichiometric defects. When ...
2
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2answers
199 views

Formation of strontium peroxide

Wikipedia states: Strontium peroxide is produced by passing oxygen over heated strontium oxide. Upon heating in the absence of $\ce{O2}$, it degrades to $\ce{SrO}$ and $\ce{O2}$. I found some ...
0
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2answers
82 views

Is there an equivalent unit cell that can describe a bcc unit cell where all points are the same element?

Similar to how an NaCl-structure can be described as just a primitive cubic structure if all the lattice points were the same element or ion. I'm asking if there any such alternative for the CsCl-...
0
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1answer
472 views

Will ice be cold or not when formed using pressure? [closed]

We know that ice can be formed either by lowering the temperature of water or by applying more pressure. If we lower the temperature of water the ice so formed will be cool which is obvious. If ice ...
1
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0answers
648 views

Body centered cubic lattice vs Primitive cubic unit cell

I was reading about Bravias lattices(cubic crystal system) when got confused about an article in my book. Please refer to Counting body center as lattice point when basis consists of 2 atoms. The ...